Judges 6:1

And the children of Israel did evil in the sight of the Lord,
&c.] After the death of Deborah and Barak, during whose life they kept to the pure worship of God, and who, perhaps, lived pretty near the close of the forty years' rest, or of the twenty years from their victory over Jabin; but they dying, the children of Israel fell into idolatry, for that that was the evil they did appears from ( Judges 6:10 ) , even worshipping the gods of the Amorites:

and the Lord delivered them into the hand of Midian seven years:
this was not the Midian where Jethro, the father-in-law of Moses, lived, which lay more southward, but that which joined to Moab, and was more eastward. This people had been destroyed by the Israelites in the times of Moses, in their way to the land of Canaan, ( Numbers 31:1 ) wherefore they might bear them a grudge, and now took the opportunity to revenge themselves on them, God permitting them so to do for their sins; and though the destruction of this people by Israel was very general, yet as some of them might make their escape, and afterwards return to their own land, and this being about two hundred years ago, might, with others joining them, repeople their country by this time, and become strong and powerful.